The disclosed invention is directed toward hose manufacturing. More specifically, the disclosed invention is directed towards a tool for imprinting a texture on a hose cover during manufacturing.
Textured hoses are known in the art, with a variety of methods to accomplish such hoses. A pattern may be generated on the outer surface of the hose due to an underlying reinforcement layer, as disclosed in U.S. Pat. No. 4,957,792. Alternatively, by corrugated the hose material and applying a fabric layer as the outermost layer, as disclosed in U.S. Pat. No. 4,307,754 or U.S. Pat. No. 4,106,967. Additionally, U.S. Pat. No. 1,749,207 discloses applying a spiny projection material on tubular articles to create a textured article.
Currently in hose manufacturing, a texture may be applied to the hose cover by a multi-step process, involving numerous man-hours and extra equipment and material that is eventually discarded after the process is employed. However, the resulting texture is not the intended result of the process, but a side benefit which the disclosed invention seeks to emulate by a quicker and cheaper process, yielding a variably textured hose which can be quickly altered to any desired texture or pattern.
The multi-step process which results in the conventionally textured elastomeric hose is accomplished by first forming the hose carcass, extruding a cover layer over the carcass, and then helically wrapping a fabric, preferably nylon, about the cover. The wrapped hose is then cured and the fabric is stripped off the hose. During curing, the hose is limited in expansion by the helically wrapped fabric, with the hose expanding into the fabric. When the fabric is stripped off, an imprint of the fabric texture is achieved on the hose cover. The resulting texture is a fine pattern with a helical strip extending the length of the hose.
The present invention eliminates the material and time consuming wrapping and unwrapping step conventionally employed. The disclosed method improves the grip charteristics of the hose. Gripping of the hose is beneficial in a variety of environments, and desired by those working in hot, cold, or wet environments. The texture imparted onto the hose by the above referenced conventional method is not an aggressive pattern and fails to provide grip characteristics to the hose.
U.S. Pat. No. 5,244,619 discloses a catheter forming process wherein the outer diameter of the catheter may be left in a rough configuration for reducing the friction characteristics. In the described process, a relatively thick layer of thermoplastic polymer is extruded onto a mandrel, and then a helically wound reinforcing material is submerged into the extruded polymer. The depth the material is submerged into the polymer is controlled by the temperature of the polymer. After the material is laid onto the polymer, and allowed to submerge, the polymer flows up creating a peaked, diamond or waffled contour.
The above method of achieving a textured surface is limited to the flow pattern of the polymer about the type of reinforcing material employed, resulting in an inconsistent pattern for the length of the hose. The present invention provides a more accurate production of a rough pattern on the external surface of an extruded hose or other tubular shaped article, ensuring a desired grip characteristic for the hose. Additionally, the present invention enables the reproduction of a variety of patterns for the hose texture.
The object of the present invention is the manufacture of a multi-layer laminate hose provided with a texture that overcomes the limitations of the current state of the art.
In accordance with the object of the present invention, an apparatus for forming a textured hose is disclosed.
The apparatus is comprised of a guide tube, drive means, and texturing means. The drive means is mounted about the guide tube and rotates the guide tube about the hose prior to texturing.
According to one embodiment of the disclosed invention, the texture means is at least one texturing element mounted on a chuck. The chuck attaches to the guide tube and rotates about the hose. The texturing elements on the chuck may be at least one, or a set of, knurled texture rollers or at least one, or a set of, scribing pens mounted on chuck jaws.
According to a second embodiment of the disclosed invention, the texture means are mounted in brackets attached to the guide tube. Mounted on each bracket a scribing pen is retained by a penholder. The scribing pen may be provided with a point for inscribing continuous lines on the hose, or a rotatable scribing roller for imprinting a continuous pattern on the hose.
The disclosed method is defined by feeding the covered hose into the texturing device while rotating the guide tube and the texturing elements about the hose. In one embodiment, when the scribing rollers are used for imprinting the texture onto the hose, the rollers also rotate upon the hose surface.